Padlock

ABSTRACT

The invention concerns a tamper-evident padlock and padlock combination. The padlock ( 10 ) has a moulded plastics lock body ( 14 ) which includes an open-ended passage ( 22 ) and an opening ( 26 ) spaced from the passage. There is also a hasp ( 16 ) which has first and second spaced apart legs ( 32, 34 ). An end ( 32.1 ) of the first leg can be located in the passage through a first end thereof while the end of the second leg can be located simultaneously in the opening. The end of the first leg in the passage can then be engaged by a breakable seal ( 20 ) which is inserted into the passage through the opposite end of the passage, in order to lock the hasp relative to the lock body. The padlock combination ( 12 ) comprises the padlock ( 10 ) and the seal ( 20 ) in combination.

This is a 371 filing of International Patent Application No.PCT/IB2003/002821 filed Jul. 16, 2003 and published on Feb. 26, 2004under publication number WO 2004/017280 A and claims priority benefitsfrom South African Patent Application No. 2002/6585 filed Aug. 16, 2002.

BACKGROUND TO THE INVENTION

THIS invention relates to a padlock.

A known padlock marketed under the name ENVOSEAL has a lock body ofmulti-part, moulded plastics construction and a metal hasp which isgenerally U-shaped. A first leg of the hasp is held captive in the lockbody in such a manner that the hasp can pivot and slide relative to thelock body between respective open and closed positions. When the hasp isin a closed position the end of its second leg locates in an opening inthe lock body and a transverse hole in the first leg aligns with atransverse hole in the lock body. A frangible plastic seal is clipped tothe lock body such that a part of the seal locates in the aligned holes.This prevents pivotal movement of the hasp from the closed to the openposition until such time as the seal is broken and removed. Breakage ofthe seal Indicates that the lock has been tampered with.

Padlocks of this kind are used in many different applications where atamper-evident seal is required. One example is in airline trolleys usedto store duty free goods, alcoholic beverages and the like. Typically,the padlock in such an application is used to lock the door or drawer ofthe trolley in a closed position.

A drawback of the known padlock described above is that it is expensiveto manufacture, partly because individually moulded plastic componentshave to be assembled about the metal hasp and then connected to oneanother to hold the hasp leg captive. Another drawback is that thedesign of the padlock dictates that it must have a fairly substantialthickness. For economy of space and packing airline trolleys have arecess to receive the installed lock but this is often too shallow toaccommodate the known lock fully. As a result the lock projects from thetrolley and can either present an obstruction or itself be impacted onand possibly damaged.

SUMMARY OF THE INVENTION

According to the invention there is provided a padlock comprising:

-   -   a moulded plastics lock body having therein an open-ended        passage and an opening spaced from the passage; and    -   a hasp which has first and second spaced apart legs, an end of        the first leg being locatable in the passage through a first end        thereof and an end of the second leg being locatable        simultaneously in the opening, the end of the first leg in the        passage being engagable by a breakable seal inserted into the        passage through an opposite, second end thereof to lock the hasp        relative to the lock body.

Preferably the lock body is of one-piece, moulded plastics constructionnad has a thickness of 8 mm or less. The hasp may be attached to thelock body by a cord or the like. Alterantively it may be attached to thelock body, typically by means of a rivet, in a manner allowing slidingand pivotal movement of the hasp relative to the lock body.

Other features of the padlock of the invention are set forth in theaccompanying description and the appended claims.

According to another aspect of the invention there is provided a padlockcombination comprising the padlock summarised above and a breakable sealhaving an insertion portion which can be engaged, by movement of theseal through the second end of the passage, with the end of the firstleg of the hasp when this end is located in the passage, thereby to lockthe hasp relative to the lock body.

Other features of the padlock combination are also set forth in theaccompanying description and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail, by way of exampleonly, with reference to the accompanying drawings in which:

FIG. 1 illustrates a padlock and padlock combination according to afirst embodiment of the invention in an unlocked condition;

FIG. 2 illustrates the same padlock and combination in a lockedcondition;

FIG. 3 shows a cross-sectional view of the padlock combination of FIG. 1in the locked condition;

FIG. 4 shows a cross-section at the line 4—4 in FIG. 3;

FIG. 5 shows a perspective view of the seal of the padlock combinationof FIG. 1;

FIG. 6 shows a cross-section at the line 6—6 in FIG. 5;

FIG. 7 shows a perspective view of a padlock combination according to asecond embodiment of the invention in a locked condition;

FIG. 8 shows a cross-sectional view of the second embodiment; and

FIG. 9 shows, in a cross-sectional view, the movement of the hasp in across-sectional view.

DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 illustrates a padlock 10 and a padlock combination 12 accordingto a first embodiment of the present invention. The padlock 10 consistsof a lock body 14 and a hasp 16. The padlock combination 12 consists ofthe padlock 10 and a seal 20.

The lock body 14 is a one-piece plastics moulding. It has a passage 22extending through it from one open end 23 to an opposite open end 25.There is a shoulder 24 adjacent the mouth of the passage at the open end25, which opens into a generally rectangular recess 27. The lock body 14also has a blind opening 26 spaced from and parallel to the passage.Relatively large and relatively small holes 28 and 30 respectivelyextend tranversely through the lock body

The hasp 16 is of 2 mm thick flat mild steel and has the shape seen inFIG. 1. It is generally of U-shape with first and second legs 32 and 34respectively, the leg 32 being somewhat longer than the leg 32. The end34.1 of the leg 34 is dimensioned to be a snug slide fit in the blindopening 26. The end 32.1 of the leg 32 is enlarged and is a slide fit inthe passage 22. It includes shoulders 32.2 and is formed with a cavity36 which is undercut by virtue of opposing, re-entrant, inclined tabs38. The tabs 38 have inclined outer surfaces 38.1 and similarly inclinedinner surfaces 38.2.

The seal 20, which, together with the padlock 10, makes up the padlockcombination 12 of the invention, is made as a one-piece plasticsmoulding. It includes a tab portion 20.1 from which an insertion portion20.2 projects. The insertion portion has a central stem 20.3 andresilient arms 20.4 which project rearwardly from the end of the stem.

In order to close the padlock, the hasp 16 is aligned with the lock body14 as shown in FIG. 1. The hasp and lock body are then moved relative toone another so that the legs 32 and 34 enter and slide into the passage22 and opening 26 respectively. When the hasp is fully inserted the end34.1 of the leg 34 abuts the blind end of the opening 26, the shoulders32.2 on the hasp abut the mouth of the passage at the open end 23 andthe end of the leg 32 abuts the shoulder 24, as shown in FIG. 2.

In order to seal the lock the seal 20 is positioned in the recess 27 andis slid, in direction opposite to that in which the hasp is inserted,into the opposite end 25 of the passage 22. When the arms 20.4 of theinsertion portion 20.2 encounter the tabs 38 they are inwardlydeflected. When the insertion portion is fully inserted the arms movepast the tabs and thereafter, with the insertion portion fully locatedin the cavity 36, spring back to locate behind the tabs, i.e. theextremities of the legs 20.4 of the insertion portion 20.2 locate behindthe tabs 38.

The insertion portion is accordingly clipped into the cavity 36 in thepassage 22, with the tab portion 20.1 lying flat in the recess 27. Itwill be understood that the seal cannot be withdrawn by a slidingaction, because this would merely draw the extremities of the legs 20.4against the inner inclined surfaces 38.2 of the tabs 38. Thus, with theinsertion portion 20.2 of the seal clipped into the cavity 36 inside thepassage 22, the hasp is effectively locked to the lock body. In order toopen the padlock, it is necessary to break the seal 20.

This is achieved by bending the tab 20.1 in a direction out of therecess 27, as indicated in FIG. 4 by the arrow 44, so that the sealbreaks at a zone of reduced thickness 20.5 between the tab and insertionportions. Once the tab has been broken off, the hasp can be withdrawnfrom the lock body and the insertion portion can be removed from thecavity 36.

Referring to FIGS. 5 and 6 it will be seen that the tab 20.1 forms arecessed, upstanding wall 20.6 adjacent the root of the stem 20.3. Whenthe insertion portion 20.2 of the seal is clipped into the cavity 36,the wall recess receives portions of the tabs 38 so that the wall liesclosely adjacent those tabs. With this feature it is difficult if notimpossible to insert a sharp tool past the tab 20.1 and into the passage22 in order to unclip the insertion portion 20.2 from the cavity 36,thereby improving the integrity of the seal.

In an application of the padlock and padlock combination to, forinstance, an airline trolley, the hasp will be arranged in the normalway to pass through openings in the components of the trolley which areto be locked to one another, eg the frame of the trolley and a door ordrawer. It will also be understood that in such applications, a visualinspection of the seal to ensure that it is not broken provides anassurance that the trolley has not been opened without authorisationprior to being brought onto the aircraft.

The large hole 28 provides a suspension point at which the padlock, onceunlocked, can be suspended from a hook or the like for re-use at a laterstage with a new seal 20.

The hasp 16 is formed with a small hole 50. This hole and the small hole30 in the lock body provide attachment points for the ends of a thincord 52 which serves to attach the hasp to the lock body, to preventinadvertant loss of the hasp.

FIGS. 7 to 9 illustrate a second embodiment of the invention which doesaway with the need for a cord 52 to attach the hasp to the lock body. Inthese Figures, components corresponding to those illustrated in FIGS. 1to 6 are indicated with the same reference numerals.

In this embodiment, the hasp 16 is permanently attached, in a mannerallowing both sliding and pivotal movement, to the lock body 14. This isachieved by means of a rivet 60 which passes through the lock body, inthe passage 22, and through an elongate slot 62 in the end 32.1 of theleg 32 of the hasp. It will also be noted that the side 64 of the lockbody is laterally extended and provides a shoulder 66 adjacent the rivet60, and that there is only a single shoulder 32.2.

FIGS. 7 and 8 show the second embodiment in a closed and lockedcondition. As in the first embodiment, the legs 32.1 and 32.2 arelocated in the passage 22 and blind opening 26, and the insertionportion 20.2 of the seal 20 is clipped into the cavity 36, inside thepassage 22, with the tab portion 20.1 of the seal lying flat in therecess 27. As before it will be understood that the hasp is effectivelylocked to the lock body by the seal when the padlock combination is inthis locked condition.

It will also be noted that in the locked position, the rivet 60 issituated at the outer end of the slot 62.

In order to open the padlock, the seal 20 is broken by bending the tabportion 20.1 in a direction out of the recess. Once the tab portion hasbeen broken away from the insertion portion, the hasp can be slidoutwardly as shown in full lines in FIG. 9. The rivet 60 slides alongthe slot 62 to its inner end as illustrated. At this stage the insertionportion 20.2 of the seal is still retained in the cavity 36. When therivet has reached the end of its travel in the slot, the hasp can bepivoted to the broken line position in FIG. 9, allowing the insertionportion 20.2 of the seal to fall out of, or be removed from, the cavity36. Abutment of the side of the hasp with the shoulder 66 preventsfurther pivotal movement of the hasp.

In order to re-lock the padlock, the opposite procedure is followed,i.e. the hasp is pivoted to the full line position in FIG. 9 and is thenslid inwardly to the FIG. 8 position, whereafter a fresh seal 20 can beclipped into place.

In both embodiments, the inclination of the tabs 38 is a securityfeature. The tabs and the upstanding wall 20.6 of the seal 20 are sodesigned that the tabs extend into the recess as will be apparent fromFIGS. 2 and 7. The tabs accordingly provide some security againstinsertion of a sharp tool into the passage 22 with the intention ofunclipping the legs 20.4 of the seal.

1. A padlock comprising: a moulded plastics lock body having therein anopen-ended passage and an opening spaced from the passage; and a haspwhich has first and second spaced apart legs, an end of the first legbeing locatable in the passage through a first end thereof and an end ofthe second leg being locatable simultaneously in the opening, the end ofthe first leg in the passage being engagable by a breakable sealinserted into the passage through an opposite, second end thereof tolock the hasp relative to the lock body, wherein the opening in whichthe end of the second leg of the hasp is locatable is a blind opening inthe lock body.
 2. A padlock according to claim 1 wherein the lock bodyis of one-piece, moulded plastics construction.
 3. A padlock accordingto claim 2 wherein the lock body has a thickness of 8 mm or less.
 4. Apadlock according to claim 1 wherein the hasp is attached to the lockbody by a cord.
 5. A padlock according to claim 1 wherein the hasp ismade of steel.
 6. A padlock comprising: a moulded plastics lock bodyhaving therein an open-ended passage and an opening spaced from thepassage; and a hasp which has first and second spaced apart legs, an endof the first leg being locatable in the passage through a first endthereof and an end of the second leg being locatable simultaneously inthe opening, the end of the first leg in the passage being engagable bya breakable seal inserted into the passage through an opposite, secondend thereof to lock the hasp relative to the lock body, the hasp beingattached to the lock body by a transverse rivet which engages the lockbody and passes through a slot in the hasp, thereby allowing sliding andpivotal movement of the hasp relative to the lock body.
 7. A padlockcomprising: a moulded plastics lock body having therein an open-endedpassage and an opening spaced from the passage; and a hasp which hasfirst and second spaced apart legs, an end of the first leg beinglocatable in the passage through a first end thereof and an end of thesecond leg being locatable simultaneously in the opening, the end of thefirst leg in the passage being engagable by a breakable seal insertedinto the passage through an opposite, second end thereof to lock thehasp relative to the lock body, the first leg of the hasp body having acavity therein which is located in the passage when the end of this legis located in the passage and into which an insertion portion of theseal is clipped in use in order to lock the hasp relative to the lockbody; wherein the opening in which the end of the second leg of the haspis locatable is a blind opening in the lock body.
 8. A padlock accordingto claim 7 wherein the lock body has a recess therein into which thesecond end of the passage opens, the recess being arranged toaccommodate a tab portion of the seal when the insertion portion thereofis clipped into the cavity.
 9. A padlock according to claim 7 whereinthe cavity is defined partly by a pair of opposing, inclined tabs at theend of the first leg of the hasp.
 10. A padlock combination comprising apadlock and a breakable seal, the padlock including a moulded plasticslock body having therein an open-ended passage and an opening spacedfrom the passage and a hasp which has first and second spaced apartlegs, an end of the first leg being locatable in the passage through afirst end thereof and an end of the second leg being locatablesimultaneously in the opening, and the seal having an insertion portionwhich can be engaged, by movement of the seal through the second end ofthe passage, with the end of the first leg of the hasp when this end islocated in the passage, thereby to lock the hasp relative to the lockbody, the insertion portion of the seal being shaped to clip into acavity in the end of the first leg of the hasp; the breakable seal has atab portion connected at a breakable connection to the insertionportion, the tab portion being arranged to be located in a recess in thelock body, into which the second end of the passage opens, when theinsertion portion of the seal is clipped into the cavity; wherein thecavity in the end of the first leg of the hasp is defined partly by apair of opposing, inclined tabs and the tab portion of the seal includesan upstanding wall which is recessed to receive the tabs when theinsertion portion of the seal is clipped into the cavity.